<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Element.php 18951 2009-11-12 16:26:19Z alexander $
 */


/**
 * Wraps a DOMElement allowing for SimpleXML-like access to attributes.
 *
 * @category   Zend
 * @package    Zend_Feed
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Feed_Element implements ArrayAccess
{

	/**
	 * @var DOMElement
	 */
	protected $_element;

	/**
	 * @var Zend_Feed_Element
	 */
	protected $_parentElement;

	/**
	 * @var boolean
	 */
	protected $_appended = true;


	/**
	 * Zend_Feed_Element constructor.
	 *
	 * @param  DOMElement $element The DOM element we're encapsulating.
	 * @return void
	 */
	public function __construct($element = null)
	{
		$this->_element = $element;
	}


	/**
	 * Get a DOM representation of the element
	 *
	 * Returns the underlying DOM object, which can then be
	 * manipulated with full DOM methods.
	 *
	 * @return DOMDocument
	 */
	public function getDOM()
	{
		return $this->_element;
	}


	/**
	 * Update the object from a DOM element
	 *
	 * Take a DOMElement object, which may be originally from a call
	 * to getDOM() or may be custom created, and use it as the
	 * DOM tree for this Zend_Feed_Element.
	 *
	 * @param  DOMElement $element
	 * @return void
	 */
	public function setDOM(DOMElement $element)
	{
		$this->_element = $this->_element->ownerDocument->importNode($element, true);
	}

	/**
	 * Set the parent element of this object to another
	 * Zend_Feed_Element.
	 *
	 * @param  Zend_Feed_Element $element
	 * @return void
	 */
	public function setParent(Zend_Feed_Element $element)
	{
		$this->_parentElement = $element;
		$this->_appended = false;
	}


	/**
	 * Appends this element to its parent if necessary.
	 *
	 * @return void
	 */
	protected function ensureAppended()
	{
		if (!$this->_appended) {
			$this->_parentElement->getDOM()->appendChild($this->_element);
			$this->_appended = true;
			$this->_parentElement->ensureAppended();
		}
	}


	/**
	 * Get an XML string representation of this element
	 *
	 * Returns a string of this element's XML, including the XML
	 * prologue.
	 *
	 * @return string
	 */
	public function saveXml()
	{
		// Return a complete document including XML prologue.
		$doc = new DOMDocument($this->_element->ownerDocument->version,
		$this->_element->ownerDocument->actualEncoding);
		$doc->appendChild($doc->importNode($this->_element, true));
		return $doc->saveXML();
	}


	/**
	 * Get the XML for only this element
	 *
	 * Returns a string of this element's XML without prologue.
	 *
	 * @return string
	 */
	public function saveXmlFragment()
	{
		return $this->_element->ownerDocument->saveXML($this->_element);
	}


	/**
	 * Map variable access onto the underlying entry representation.
	 *
	 * Get-style access returns a Zend_Feed_Element representing the
	 * child element accessed. To get string values, use method syntax
	 * with the __call() overriding.
	 *
	 * @param  string $var The property to access.
	 * @return mixed
	 */
	public function __get($var)
	{
		$nodes = $this->_children($var);
		$length = count($nodes);

		if ($length == 1) {
			return new Zend_Feed_Element($nodes[0]);
		} elseif ($length > 1) {
			return array_map(create_function('$e', 'return new Zend_Feed_Element($e);'), $nodes);
		} else {
			// When creating anonymous nodes for __set chaining, don't
			// call appendChild() on them. Instead we pass the current
			// element to them as an extra reference; the child is
			// then responsible for appending itself when it is
			// actually set. This way "if ($foo->bar)" doesn't create
			// a phantom "bar" element in our tree.
			if (strpos($var, ':') !== false) {
				list($ns, $elt) = explode(':', $var, 2);
				$node = $this->_element->ownerDocument->createElementNS(Zend_Feed::lookupNamespace($ns), $elt);
			} else {
				$node = $this->_element->ownerDocument->createElement($var);
			}
			$node = new self($node);
			$node->setParent($this);
			return $node;
		}
	}


	/**
	 * Map variable sets onto the underlying entry representation.
	 *
	 * @param  string $var The property to change.
	 * @param  string $val The property's new value.
	 * @return void
	 * @throws Zend_Feed_Exception
	 */
	public function __set($var, $val)
	{
		$this->ensureAppended();

		$nodes = $this->_children($var);
		if (!$nodes) {
			if (strpos($var, ':') !== false) {
				list($ns, $elt) = explode(':', $var, 2);
				$node = $this->_element->ownerDocument->createElementNS(Zend_Feed::lookupNamespace($ns),
				$var, htmlspecialchars($val, ENT_NOQUOTES, 'UTF-8'));
				$this->_element->appendChild($node);
			} else {
				$node = $this->_element->ownerDocument->createElement($var,
				htmlspecialchars($val, ENT_NOQUOTES, 'UTF-8'));
				$this->_element->appendChild($node);
			}
		} elseif (count($nodes) > 1) {
			/**
			 * @see Zend_Feed_Exception
			 */
			require_once 'Zend/Feed/Exception.php';
			throw new Zend_Feed_Exception('Cannot set the value of multiple tags simultaneously.');
		} else {
			$nodes[0]->nodeValue = $val;
		}
	}


	/**
	 * Map isset calls onto the underlying entry representation.
	 *
	 * @param  string $var
	 * @return boolean
	 */
	public function __isset($var)
	{
		// Look for access of the form {ns:var}. We don't use
		// _children() here because we can break out of the loop
		// immediately once we find something.
		if (strpos($var, ':') !== false) {
			list($ns, $elt) = explode(':', $var, 2);
			foreach ($this->_element->childNodes as $child) {
				if ($child->localName == $elt && $child->prefix == $ns) {
					return true;
				}
			}
		} else {
			foreach ($this->_element->childNodes as $child) {
				if ($child->localName == $var) {
					return true;
				}
			}
		}
	}


	/**
	 * Get the value of an element with method syntax.
	 *
	 * Map method calls to get the string value of the requested
	 * element. If there are multiple elements that match, this will
	 * return an array of those objects.
	 *
	 * @param  string $var    The element to get the string value of.
	 * @param  mixed  $unused This parameter is not used.
	 * @return mixed The node's value, null, or an array of nodes.
	 */
	public function __call($var, $unused)
	{
		$nodes = $this->_children($var);

		if (!$nodes) {
			return null;
		} elseif (count($nodes) > 1) {
			return $nodes;
		} else {
			return $nodes[0]->nodeValue;
		}
	}


	/**
	 * Remove all children matching $var.
	 *
	 * @param  string $var
	 * @return void
	 */
	public function __unset($var)
	{
		$nodes = $this->_children($var);
		foreach ($nodes as $node) {
			$parent = $node->parentNode;
			$parent->removeChild($node);
		}
	}


	/**
	 * Returns the nodeValue of this element when this object is used
	 * in a string context.
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->_element->nodeValue;
	}


	/**
	 * Finds children with tagnames matching $var
	 *
	 * Similar to SimpleXML's children() method.
	 *
	 * @param  string $var Tagname to match, can be either namespace:tagName or just tagName.
	 * @return array
	 */
	protected function _children($var)
	{
		$found = array();

		// Look for access of the form {ns:var}.
		if (strpos($var, ':') !== false) {
			list($ns, $elt) = explode(':', $var, 2);
			foreach ($this->_element->childNodes as $child) {
				if ($child->localName == $elt && $child->prefix == $ns) {
					$found[] = $child;
				}
			}
		} else {
			foreach ($this->_element->childNodes as $child) {
				if ($child->localName == $var) {
					$found[] = $child;
				}
			}
		}

		return $found;
	}


	/**
	 * Required by the ArrayAccess interface.
	 *
	 * @param  string $offset
	 * @return boolean
	 */
	public function offsetExists($offset)
	{
		if (strpos($offset, ':') !== false) {
			list($ns, $attr) = explode(':', $offset, 2);
			return $this->_element->hasAttributeNS(Zend_Feed::lookupNamespace($ns), $attr);
		} else {
			return $this->_element->hasAttribute($offset);
		}
	}


	/**
	 * Required by the ArrayAccess interface.
	 *
	 * @param  string $offset
	 * @return string
	 */
	public function offsetGet($offset)
	{
		if (strpos($offset, ':') !== false) {
			list($ns, $attr) = explode(':', $offset, 2);
			return $this->_element->getAttributeNS(Zend_Feed::lookupNamespace($ns), $attr);
		} else {
			return $this->_element->getAttribute($offset);
		}
	}


	/**
	 * Required by the ArrayAccess interface.
	 *
	 * @param  string $offset
	 * @param  string $value
	 * @return string
	 */
	public function offsetSet($offset, $value)
	{
		$this->ensureAppended();

		if (strpos($offset, ':') !== false) {
			list($ns, $attr) = explode(':', $offset, 2);
			// DOMElement::setAttributeNS() requires $qualifiedName to have a prefix
			return $this->_element->setAttributeNS(Zend_Feed::lookupNamespace($ns), $offset, $value);
		} else {
			return $this->_element->setAttribute($offset, $value);
		}
	}


	/**
	 * Required by the ArrayAccess interface.
	 *
	 * @param  string $offset
	 * @return boolean
	 */
	public function offsetUnset($offset)
	{
		if (strpos($offset, ':') !== false) {
			list($ns, $attr) = explode(':', $offset, 2);
			return $this->_element->removeAttributeNS(Zend_Feed::lookupNamespace($ns), $attr);
		} else {
			return $this->_element->removeAttribute($offset);
		}
	}

}
